Alarm device for indicating failure of the paper feed mechanism in teleprinters



Oct. 23, 1951 R. D. SALMON ALARM DEVICE FOR INDICATING FAILURE OF THEPAPER FEED MECHANISM IN TELEPRINTERS 2 SHEETSSHEET 1 Filed Oct. 22, 1946Oct. 23, 1951 R. D. SALMON 2,572,057 ALARM DEVICE FOR INDICATING FAILUREOF THE PAPER FEED MECHANISM IN TELEPRINTERS 2 SHEETSSHEET 2 Filed Oct.22, 1946 Inventor W44! M Ma y Attorney Patented Oct. 23, 1951 UNITEDSTATES PATENT OFFICE ALARM DEVICE FOR INDICATING FAILURE OF THE PAPERFEED MECHANISM IN TELEPRINTERS Application October 22, 1946, Serial No.704,975 In Great Britain July 19, 1945 Section 1, Public Law 690, August8, 1946 Patent expires July 19, 1965 8 Claims.

This invention relates to an alarm device for indicating failure of thepaper tape to feed in a teleprinter, more particularly when the tape isof the gummed tape kind.

Heretofore there has been devised a paper feeding mechanism for feedingthe tape in a teleprinter, in conjunction with alarm devices forindicating failure of proper operation of the tape feeding mechanismwhereby the alarm was given should the feeding rollers fail to grip thepaper tape or should the paper tape break, in either of which cases themechanism would fail to tension the tape.

It sometimes happens, particularly with gummed tapes, that the papertape becomes stuck in the roll and fails to feed, although it may notbreak, and the feature of the present invention is to provide in a tapeteleprinter, mechanically operated means whereby an alarm device isoperated should the tape become gummed in the feed roll or becomesimilarly seized, even though the tape should not actually break.

The invention is particularly suit-able with a teleprinter of the typewherein the tape is to be guided around a printing platen which platenis carried by a hinged frame which, when in closed position, positionsthe platen in proper printing relation with respect to a series ofprinting bars. In such a construction, it is necessary therefore, inorder to secure proper printing, that the hinged frame which carries theplaten, the tape feeding and inked ribbon reversing mechanism, becompletely closed, so as to maintain the proper relation between theprinting platen, the tape, and the type faces. In addition, an object ofthe present invention is to arrange the alarm device to be actuated ifthe frame on which is mounted the paper feeding, ink ribbon andreversing mechanism, is inadvertently left swung away from or not closedup to the typewheel, that is, when not in its normal operative position.

The alarm signal may be audible and/ or visual and the arrangement ofthe invention acts mechanically and positively without recourse to timerelays such as slow-acting relays which have heretofore been required inorder to give an alarm.

One embodiment of the invention is hereinafter described and illustratedin Figs. 1, 2 and 3 of the accompanying drawing.

The several figures illustrating the embodiment are:

Fig. 1, a view, with parts broken away, of the frame, on which ismounted the paper feeding,

ink ribbon feeding and reversing mechanism, in its normal operativeposition of juxtaposition with the typewheel.

Fig. 2, a view of the relevant parts of the paper feeding mechanismincluding the alarm mechanism shown in relation to the teieprmter butwith the supporting framework and cover omitted for the sake ofclearness.

Fig. 3, a view of the mounting frame of Fig. 1, swung away from thetypewheel.

As shown more clearly in Figs. 1 and 2, the gummed tape 7 is arranged tobe taken off a suitable supply reel (not shown) and fed in the directionof the arrow, so that it passes between a pair of jaws and thence asindicated by the dot-dash line it passes around a pulley roller H fromwhich it is partially looped, and passes around the printing platen ll.After leaving the platen H, the tape passes between the feed rollers l8,19. The feed roller I9 is arranged to be operated in a step-by-stepmanner by means of a suitable ratchet wheel l9a I and pawl i9b, which inturn are arranged to be operated in timed relation by any suitablemechanism including, for example, the swingable lever 42b as describedin detail in co-pending U. S. application, S. N. 589,247, now Patent No.2,480,165.

The tape guide or jockey roller I1 is attached to a lever 20 which ismounted for rotation at point 2! for pivotal movement in a horizontalplane. The end of lever 20 is urged in a clockwise direction by asuitable spring 41, thus causing roller I1 resiliently to engage thetape 1 so as to maintain it under a predetermined tension. Downwardlydepending from lever 20 is a pin 44, which is adapted to engage a triparm 42, normally held in resilient engagement with pin 44 by a suitablespring 420.. The free end of lever 42 is adapted to engage the latch 48which is pivotally mounted at 48a. Latch 48 may be held in resilientengagement with the end of arm 42 by a suitable spring 481). Latch 48has a rectangular opening 19 to permit the arm 42 to pass freelytherethrough when said arm is in alignment with said opening. Thehorizontal position of arm 42 with respect to opening 19, will thereforebe dependent upon the position of lever 20, which in turn will bedependent upon the tension in tape 1. The tape when normally tensioned,maintains the lever 20 in such a position that the pin 44 holds the arm42 in registry with opening 19, so that any movement of the arm 42perpendicular to the latch 48 as a result of clockwise rotation ofmember 422), does not disturb the position of this latch. However, thetape'] is over-tensloneo as a result, for example, of ts sticking eitherat the supply reel or at any other intervening point, it causes thelever zu to be rotated counterclockwise, thus pushing arm 42 to the leftso that it is no longer in registry with opening l9. On the other hand;if the tape should actually break at any point, the spring 41 causes thelever to to be rotated clockwise as aresult of which the arm 42 moves tothe right of opening is. From the foregoing, it will be seen that thearm as, which may be referred to as the alarm controlling member, canassume three sep arate positions. In one position, corresponding tonormal tension of tape 7, it is in alignment with opening iii. Inanother position,-it.-is to the right of this opening corresponding to abreakage of the tape. In the third position, it is to theleft of openingi9 corresponding to a blocking of the tape at any point in its'i'eedingmovement. Arm i2 is pivotally attached at iZd to the member $21) whichcontrols the feeding movement of the ratchet i922. The member 5212 isarranged to be oscillated about a pivot point 620 by the usual tapefeeding mechanism. When the member eZb is oscillated in a clockwisedirection, it causes *member 42 to push latch ill clockwise. Normallyhowever, the latch 48 is held by its spring set so that its detent i8 isin engagement with the contact controlling lever 80, and the lever 8i)is restrained from closing the alarm circuit contacts e3 The lever 8b ispivoted on a horizontal axis 58 and is held by a spring 5| against thedetent 118 on the lower edge of latch 48 whereby latch 58 normally liesin the path of lever Bil.

In the event of failure of proper action of the paper feeding mechanismwhereby the mechanism fails to tension the'tape, the end of the trip armt2 engages latch 48 onone side OI the rectangular hole '39 therebyremoving latch 58 from the path of lever 86] so that spring 5i rotatesthis lever sufficiently, to close alarm contacts 53.

In the event of failure of the paper tape to feed due to gumming of thetape in thefeed roll or similar seizure, the loop oftapep'assing aroundthe printing platen ii will be successively shortened by action of thefe'edingrollers l8, it thereby retracting pulley roller it againstspring 4? beyond its normal moved position. Trip arm 42 is thenrotatedcounterclockwise, viewedfrom above, by the pin i4, whereby triparm 42 engages with latch is on the other corresponding side of therectangular hole i9. Latch 48 is thereby removed from the path of lever8i] so that spring 5| rotates lever Bi] sufliciently to close alarmcontacts 53.

Preferably the machine is provided with an enclosing casing 9 whichhouses the usual typeselecting mechanism and has a suitable openingthrough which a selected type bar (not shown) can be moved towards theplaten llpas described in application SerialNo. 592,172, filed May 5,1945, now Patent No. 2,483,4l6, .Hingedly.

attached to the casing 9 isan inverted L'-shaped frame If], the verticalwall of which carries the spools Hi for the inked ribbon o. Thehorizontal wall of the frame it carries the rotatably mounted platen lltogether with the .latch 38 and the tape-feeding mechanism including clementsl'l, l8, l9, I9a, i9b, 2fi, 21, 42, lga flb, 48, 48a, 18, 79, asillustrated in Fig. 2, whereas the lever 86 and the alarm circuitcontacts 53 are mounted on a suitable fixed frame (not shown) whichcarries the usual type-selecting mechanism interiorly of easing ,9. Itwill be seen, therefore, that in order to eifect proper engagementbetween the platen H, the inking ribbon 6 and the tape 1, it isnecessary that the frame id be completely closed. If this frame is notcompletely closed, the latch F8 on member 38 is not in engagement withthe upper end of lever 86 so that this lever is held in itscounterclockwise position ,by spring 5i to close the .alarm circuitcontacts 53.

Figs. 1 and 3 of the accompanying drawing illustrate respectively thenormal operative position of the frame Hi and some opened position togive access to the typewheel which according to the present inventionwill actuate the alarm signal. This is effected, as follows:

The latch 48 is mounted with the paper feeding mechanism on the'frameit, whereas the pivot 58, carrying the lever Be is mounted. on a fixedportion of the machine. Then, if the frame ii! is moved from its normalposition (Fig. 1) to some opened position (Fig. 3) the latch 48 will bemoved away from lever all, thereby permitting the spring 5| to rotatethe lever 80, thereby closing the alarm actuating contacts 53.

What is claimedis: a

1. Alarm actuating apparatus for use with a tape feeding mechanismcomprising tape guiding means, a biasing spring, said means adapted toengage the tape and to have a predetermined normal, lateral positioncorresponding to normal tape tension, to be laterally shiftable againstthe tension of said spring in one direction away from said normalposition upon sticking of the tape, to be laterally shiftable uponactuation of said spring in the other direction away from said normalpositionupon breakage of the tape, an alarm operating element comprisinga pair of switch contacts anda pivoted'lever adapted to actuate saidcontacts, said lever spring-biased to operating position; latching meansrotatable about an axis disposed at a right angle to the pivotal axis ofsaid lever, said latching means normally engaging said lever to restrainsame from actuating saidedntacts, said latching means provided with anaperture therethrough, trip means, meansto reciprocate said tripmeansagainst said latching means, and for urging said latching means out ofengagement with said lever when said guiding means is in a positionotherthan normal, said trip means adapted to pass through the aperture 1in said latching means only when said guiding means is in normalposition, whereby said contacts are actuated when said tape guidingmeans shifts in either direction from n-ermal position. a

2. A tape feeding mechanism according to claim 1 wherein the means toreciprocate said trip means m r ses adesflfieieb ta f lever, said tripmeans being p'ivotally attached to said tapefeed lever a pinmovable as aunit tape feeding mechanism as, claimed inclaim 1,

wherein said tape jg ding mea compri e an additional pivotedleverpapulley roller rotatably mounted at one end of said additional lever,said biasing spring attaehed to theotherend or. i .addiim il rer i .nrmai m gi esai roller into engagement with the tape to tension same, andwherein said latching means com-' prises a latch plate having a detentat one extremity thereof and a pivot at the other extremity thereof, anadditional spring for normally urging said plate and detent intoengagement with said pivoted lever.

4. A tape feeding control mechanism according to claim 1, wherein saidtape guiding means further comprises a pin which abuts against said tripmeans, and wherein said trip means is pivotally connected at one endthereof to said trip reciprocating means; a further spring adapted tourge said trip means against said pin; said latching means extendingtransversely and having its aperture in alignment with the other end ofsaid trip means only when the tape is under normal tension, saidlatching means further comprising detent means in latching engagementwith said contact actuating lever.

5. A tape feeding mechanism according to claim 1, wherein said tripmeans comprises a trip arm having a free end and having its other endpivotally connected to said trip reciprocating means, said tape guidingmeans comprises a pin in sliding contact with said trip arm, said pinadapted to control lateral movement of the free end of said trip armwith respect to the aperture in said latching means, said trip armadapted to assume a first position corresponding to alignment with theaperture in said latching means when normal tape tension exists, asecond position on one side of the aperture in said latching means whenabnormal tape tension exists and a third position on the other side ofthe aperture in said latching means when no tape tension exists, saidlatching means comprising a detent to normally hold said contactactuating lever in a position in an unoperated position when said triparm is reciprocated while in its first lateral position, said detentadapted to release said contact actuating lever to an operated positionwhen said trip arm is reciprocated while in either its second or thirdlateral position.

6. An alarm control arrangement for the feeding mechanism of a tapeprinter and the like, comprising means adapted to guide a message tapethrough said printer, an alarm operating element comprising a pair ofnormally open alarm circuit contacts and a pivoted lever for operatingsaid contacts, a latch member having two positions in one of which itrestrains said lever from closing said contacts and movable to anotherposition where it frees said lever to close said contacts, a. pivotallymounted arm also movable transversely to said latch member, tape feedmechanism for causing said transverse movement of said arm, said armbeing arranged to assume selectively one of three different pivotedpositions with respect to said latch member, one of said positionscorresponding to normal tape tension and in which it is ineffective tomove said latch member.

7. An alarm control arrangement according to claim 6, wherein said meansadapted to guide a message tape through said printer further comprises apulley roller, said pivotally mounted arm being engaged by an operatingpin for controlling its said three positions; said pin being attached tosaid roller.

8. A tape feeding control mechanism for tape teleprinters and the like,comprising a platen around which a message tape is adapted to be guided,a pair of tape guides at least one tape guide laterally offset withrespect to said platen, means resiliently urging said one guide againstthe tape to provide a normal tape tension around said platen, an alarmoperating element comprising a pair of switch contacts and a pivotedlever spring biased to operating position, means mechanically coactingwith said lever to hold it in a position corresponding to normal tapetension whereby said contacts are not actuated, a trip arm, a pin membercontrolled by said one tape guide for controlling the movement of saidtrip arm to one of three pivoted positions, a tape feeding controlmember for reciprocating said trip arm, said mechanical coacting meansselectively controlled by the reciprocating motion of said trip arm andin accordance with the pivotal position of said trip arm.

REGINALD DENNIS SALMON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,202,952 Adams Oct. 31, 19161,343,910 Evans June 22, 1920 1,361,860 Holt Dec. 14, 1920 2,142,880Anderson Jan. 3, 1939 2,179,517 Pelosi Nov. 14, 1939 2,214,609 DrakeSept. 10, 1940 2,410,521 Potts Nov. 5, 1946 FOREIGN PATENTS NumberCountry Date 490,368 Great Britain Aug. 11, 1938

